SORPTION OF HEAVY-METALS BY UNTREATED RED FIR SAWDUST

Equilibrium and rate relationships have been determined for the sorption of divalent copper (Cu2+) and hexavalent chromium (Cr6+) onto untreated Red Fir sawdust. For both ions, the equilibrium sorption levels were determined to be a function of the solution pH and temperature. The equilibrium adsorption capacity of the sawdust for Cu2+ was found to increase with increasing pH. However, for Cr6+ the sorption capacity increased with decreasing pH. For both ions, the rate of adsorption and the equilibrium adsorption capacity increased with temperature. The sorption capacity of alpha-cellulose was at least an order of magnitude less than the untreated sawdust.